Scottish archaeologists have discovered the world's oldest known lunar calendar--a series of 12 large, especially shaped pits, around 10,000 years old, that were designed to mimic the various phases of the moon. The pits align perfectly on the midwinter solstice in a way that would have helped the hunter gathers of Mesolithic Britain keep accurate track of the passage of the seasons and the lunar cycle. Thisis older than Stonehenge, which was built sometime between 3000 BC and 2000 BC. These pits pre-date all other calendars so far discovered, but are surprisingly sophisticated, designed so that changes can be made periodically to keep up with the precession of the equinox. Considering their age, this is an amazing and unexpected finding. So it's worth taking a look at the world as it was when they were created.
The world of 10,000 years ago had just come through a catastrophe of fantastic proportions. The ice age had ended with the dramatic collapse of the Laurentide Glacier, a massive fire that swept the North American continent, leaving behind a geologic feature we know today as the 'black mat,' a mix of ash from the fires and dead algae from subsequent flooding. The land bridge that had linked the British Isles to the European continent had been permanently flooded as sea levels, between 12,000 and 10,000 years ago, rose 200 feet.
In Turkey, the mysterious and enormous Gobekli Tepe ritual site was in the process of being methodically buried, a gigantic undertaking that would have lasted hundreds of years. If geologists are correct, the Sphinx had just been built in Egypt. And in far northern Scotland, this simply constructed but sophisticated calendar was being built, designed to remain accurate over thousands of years.
Were the societies capable of these massive works and sophisticated measurements really simple hunter-gatherer cultures? It is always worth remembering just how deep a mystery is the human past.